The existing cellular telephone industry involves crowded product and services markets. Companies are endlessly competing to launch new products with improved technologies. At the same time, manufacturers are constantly working to provide easy-to-use phone designs that provide maximum conceptual impact with a minimum amount of production and construction effort. The endless competitive cycle encourages manufacturers to produce different shapes and sizes of phones to distinguish their phones from the phones of their competitors. Generally, each phone of a different shape and size demands a different housing which, in turn, decreases part consolidation between different phones because parts for one phone will not work on or fit in another phone. A decrease in part consolidation is increasingly problematic as the complexities of cell phones and the attempts to change the appearance of the phones causes increasing field failure rates (FFR).
Previous attempts to customize user-interfaces include specialized housings that are created using many small parts, including, for example, a rigid front cover, a window, a moving keymat, and a back cover, each coupled to the cell phone engine or chassis. As noted above, every specialized part designed for a phone having a different appearance, decreases part consolidation. Field failure repairs become more costly to a manufacturer when replacement parts, for example replacement housings or displays for broken or scratched housings or displays, require specialized parts for a particular phone. Similarly, many specialized housing shapes require internal components to be manufactured in corresponding specialized shapes, also decreasing part consolidation increasing the field failure repair costs for internal component damage.
A present method of changing the appearance of phones without designing specialized housings and corresponding specialized parts that decrease part consolidation is to provide interchangeable housings to the customers. See, for example, U.S. Pat. No. 6,594,472 to Curtis et al. While this type of cover has been readily accepted by the market and often provides quick replacement housings, these interchangeable covers are limited in application, variety, build strength, and unit protection. Interchangeable covers and locking mechanisms often are made of hard plastic that is susceptible to breakage or requires complicated assembly procedures. The hard plastic may crack or break when a phone is dropped, and a hard plastic cover does not provide substantially increased protection for the internal components of the phone unit. A snap on housing assembly may be hard to remove or may crack or break as a result of an improper assembly attempt, under the required forces for assembly, or from repetitive wear of a user manipulating the snapping assembly such as from play or a nervous or fidgeting habit. Also, with these types of interchangeable housing covers, internal components may be exposed when an interchangeable housing is removed, allowing the internal components to become loose, detached, or even break.
Existing interchangeable phone covers made from hard plastic materials are also limited in the variety of appearances for phones. Typically, a portable telephone or personal digital assistant (PDAs) has a keypad and a window or display integrated into the front of the phone or personal digital assistant unit. A display window or screen provides visual information for the user to operate the phone, and a keypad allows the user to input data and control the operation of the phone or personal digital assistant. An alphanumeric keypad is usually included and has at least ten keys corresponding to the numbers 0 to 9, typically also including keys for # and * symbols. Function keys are also usually included and may provide on and off control or activation and suspension modes for a device, menu functions, cursor movement for at least up and down and left and right directions, volume adjustment, and selection commands. Phones may now also include specific keys for digital picture, email, and web browsing functions. As such, different models of phones often require different keymats. However, existing interchangeable phone covers made from hard plastic materials cannot be made with different keymat designs because the keyholes of a hard plastic cover must correspond to a fixed keypad design incorporated on the phone.
Existing phones and covers therefore do not provide sufficient variability to accommodate one repeatedly changing size and shape of cellular telephones and similar personal electronic products, while at the same time being interchangeable to reduce part count and providing the necessary protection for the internal electronics.
A new type of housing or covering is needed to improve the ability to alter the appearance of a phone while maintaining or increasing part consolidation, providing a durable replacement housing, and allowing for varieties in display windows or screens and keymat assemblies. An interchangeable housing or cover that decreases the field failure rate of phone and personal digital assistant components, particularly internal components, is also needed.